How to get the drop-down list value and number of elements in js

例子，js获取下拉列表框元素个数。

<script></li>
<li>function getLength()</li>
<li>{</li>
<li>alert(document.getElementById("mySelect").length);//元素个数</li>
<li>}</li>
<li></script>




  Apple
  Pear
  Banana
  Orange